You can look at the generated interface. name, e.g. But it's not just the language contributing to it. For more information, visit the page for this site at developer.apple.com and check out Swift.org, the homepage of the open source Swift project where you can see all of the Swift evolution. I can't banish a Boolean constant to anywhere. Avoid obscure terms if a more common word conveys meaning just So, in Swift, a function name is comprised, of so-called base name, which here is remove in both. to the actual operation of removing boxes. Protocols that describe a capability Yes! And that corresponds to the mutating form. So, we're going to talk through what that means for your code. this is also fine in the same program: However, these index methods have different semantics, and should Because what is your mind doing as you're reading through this verbose code? So, remove item ted from the list of friends. And of course, the compiler will validate that that property exists, that it's exposed to Objective-C and get the right Objective-C name for it. So I'm going to put up a bunch of code here. “sin(x)” has been in common use among programmers for decades, But of course, these guidelines, they're not interesting unless they actually are widely applied. For example, consider a method that removes the element at a Actually, now that I look at this, I think this code can even simpler. /// - **Parameter separator**: text to be printed , /// between items. And that will be reflected in your generated headers and all of the metadata and everything else so you get specific control over the Objective-C names, but no other part of your Swift code actually has to care about this. I'm here with my colleague Michael Ilseman. Now, one of the reasons this works so beautifully in Swift is, that it has a strong static type system to make sure. So all of the information you need to understand those APIs. The access to the User Handbook is … If you were to do something truly inadvisable, like for example, try to remove caffeine from your list of friends, you're going to get an error message from the compiler telling you that that doesn't make sense. So it's a little bit of English grammar here. So for these cases, you can use the @objc attribute. CGColorCreateGenericRGB as well as all of the other many. ambiguities in the presence of type inference. Here I want to remove element caffeine from a list of organic compounds. if it'd help your understanding, of course. Previous message: [swift-evolution] [Review] SE-0023 API Design Guidelines Next message: [swift-evolution] [Review] SE-0023 API Design Guidelines Messages sorted by: I’m not committed one way or another on particular style, as long as it is either consistent or there is a clear line drawn. We don't need a first argument label to make it read well. And these wonderful APIs we use. Now Core Graphics has a lot of different global functions to create all different kinds of CG Affine Transforms. These are actions taken. item for details. Often, an API can be completely understood from its declaration and appending “ed”): When adding “ed” is not grammatical because the verb has a direct When evaluating a design, reading a declaration is seldom sufficient; always examine a use case to make sure it looks clear in context. Now, you can overload based on type information. So let's look at another API and try to talk about when a word actually is needed to help describe an argument. But it's always been there. • Consistency with Cocoa/Foundation. That's fine. that sidebar is going to be a view of some sort. Name functions and methods according to their side-effects. to create all different kinds of CG Affine Transforms. /// Returns `true` iff `self` contains an element equal to. And we don't really like global functions, of course. Highly recommend that you read them and try, they're not interesting unless they actually are, Which is the application of these guidelines, to the Swift Standard Library, to the Cocoa, and Cocoa Touch APIs as well as targeted improvements to APIs. participle (usually Clarity is more important than brevity . It's stating that this argument here will become a child. This brings us to naming and the idea of naming. Below that the generated Swift interface. To facilitate use as a quick reference, the details of many guidelines Because good design makes us more productive. elements. • Conventions make code easier to read and review. and provide expressive access to tuple members. This talk will explore the philosophy behind the Swift API Design Guidelines and their application throughout the Swift Standard Library and the Cocoa and Cocoa Touch APIs. And any global variables of this type will get imported automatically as static properties of this type. Now, when you're dealing with value types, it's sometimes the case that you have both a mutating. in that case do not form part of a grammatical phrase, so they You can't fix this bad code with your API alone. That is, other modules may want to define their own. to get the setter or the getter respectively. API Design Guidelines in Swift. appropriate. Clarity is more important than brevity. Now, these guidelines were designed for a different language with a different character. So all of the information you need to understand those APIs and how they work is there in the contextual information. AnyObject, and unconstrained generic parameters) to avoid automatically as static properties of this type. In “narrowing” type conversions, though, a label that describes when you're implementing optional protocol methods. and the method above that you actually meant to call. trying to understand the API. Use recognized by pretty much every Swift app out there. Has one name that's appropriate for Objective-C. and one name that's appropriate for Swift. Protocols that describe what something is should read as nouns (e.g. That's mutating. uses. So I'm going to start with what you get for free automatically. Very straightforward. In practice, this guideline along with those for If you have code that is too terse, then you're missing critical information that you need to understand that code. Now, you'll notice that there's actually two things. SWIFT Standards works with the user community to specify and publish Market Practice - rules and best-practice advice on how standards should be deployed to meet particular business needs or to comply with regulation. Let's read this out remove at the position of former friend. Swift has matured significantly in the years since this answer was written. We rotate it. So, our attempt at using some innocuous word here to describe the argument has actually led us to less clear use cases. give it an argument label. closure arguments that appear at the call site are not supported. This is also known as, "Oh, no! If you were to do something truly inadvisable, like for example, try to remove caffeine from your list, of friends, you're going to get an error message. a single abstraction. Note: the ability to retrieve the original value has no bearing grammatical English phrases. So, let's revisit the code from before. So we're looking for this sort sweet spot in the middle. So in Swift 3 we introduced a new attribute just for this use case. Begin with a summary that describes the entity being declared. So you get a consistent, whole experience of working with beautiful Swift code. to this view argument that is our first argument. For example: Default arguments are generally preferable to the use of method People will look at that API in code, or maybe look at the documentation for it a couple of times. At a high-level, I really get no sense on how APIs are really supposed to be developed in Swift. It is better to name a contiguous data structure Array than to I'm going to focus on Core Graphics. And of course, the compiler will validate, that that property exists, that it's exposed to Objective-C. and get the right Objective-C name for it. Does it skew toward safety, performance? The following would be grammatical but would express the wrong It's more important than having brief code. • Improving clarity and readability. In all cases, this is a zero cost overhead. There is a long debate going on the internet, about the best ways to design the APIs, and is one of the most nuanced. Also, in Swift 3 NSCalendar, it's now just known as Calendar. That said, concise code does happen in Swift. A raywenderlich.com subscription is the best way to learn and master mobile development — plans start at just $19.99/month! In this case, the word Element adds nothing salient at the call In the new Swift API design guidelines, the commonly-used Type suffix for protocols is being dropped. It's more important than having brief code. This is why in Swift 2.2 we introduced #selector. Paragraphs are separated by blank lines and use complete You get to refer to a dotted sequence of property accesses. when it's being migrated from Swift 2 to Swift 3. As a Swift programmer, most of the time you don't need to care. So focus on proper use cases. And so we write out a use case. I'm here and I have a nice big name." phrase, omit its label, appending any preceding words to the base You may have a mixed project with Objective-C code in it that needs to refer to the names in your Swift code. But, clear code has to hit the correct point in this sort, And if you think about what is verbose code, verbose code is. describes a parameter’s role rather than its type. So, we have method names and we have types. Well, we know from the static type system that sidebar is going to be a view of some sort. the answer is just an option click away inside Xcode. You can also import as an instance member. verb’s imperative for the mutating method and apply the “ed” or or a fundamental type such Int or String, type information and defaults provides a vastly superior programmer experience. You get to refer to a dotted sequence of property accesses. It has optionals, so you have to consider the possibility of nil everywhere. And you can see Swift rendering an opinion about certain things here. There are no official guidelines defined for the same. Now you'll get a warning with a Fix-it to fix up the names so you can be sure that your method will be called properly. And so, when you bring all of these APIs that were written for Objective-C into Swift unmodified, they seemed a little bit out of character. e.g. Use a single sentence fragment if possible, ending with a Swift code is compact compared to Objective-c, but that is not a goal in API Design. And this code is not clear anymore. But that comes from using the right contextual cues. Omit needless words. Works with code completion. It's a lot of change. It's just restating information that's already, in the strong static type system that will be enforced. All of your Objective-C APIs are available in Swift. Reverse it. So, how could we take an API like this and make it look Swifty? So we've extended NS Swift Name. And names like this handleDragWithSender for just don't feel right when they're in Objective-C. /// element of `items` to the standard output. Abbreviations, especially non-standard So, how will this API look if we were going to design this fresh in Swift 3? in Swift 2 is going to change in some sense in Swift 3. That verbosity is all of these explicit type annotations. But this word child is clarifying the role of this parameter in the operation. What do we write here? How can we make it feel Swifty? Now, method names will get you a long way towards a Swifty API, but this doesn't quite go far enough. Parameters without defaults are usually more The Swift compiler will inspect names in order to eliminate redundant type information. Use your generated interfaces, the documentation. API Design Guidelines in Swift. But their argument labels are different because they do different things. SWIFT OAuth Token API is used to issue tokens needed to access other SWIFT API products. because we're probably using value types here anyway. So my first API here removeBoxes (withLabel:WWDC). already possesses should be omitted. And in parentheses put the exact Objective-C name that you want. We don't need that extra variable result. This is usually when we have an argument here. they seemed a little bit out of character. especially NSCalendarIdentifierGregorian. Okay. Don’t surprise an expert: anyone already familiar with the term For example, if you're wiring up target action. So, when you name a method, name it based on its side effects. This is usually when we have an argument here. preposition, So you get nice Objective-C APIs for your Swift code. I'm going to start with a couple Objective-C APIs as they were imported into Swift 2. Now, when you're coming up with first argument labels, again. Why? symbol command syntax. have a label unless the call is performing a is printed. And we will be focusing on the Swift use site and improving the Swift use site. as part of the API Design Guidelines document. This guideline implies that if the first argument doesn’t form code can be compact, it is a non-goal But essentially it's withLabel. Well, for one, it's just a simple numbers game. It doesn't know your intent. This repository is part of the Swift 3 API Design Guidelines effort, which helps evaluate the effects of applying the Swift API Design Guidelines to Objective-C APIs through improvements to Swift's Clang importer. And that's all you'll deal with. Streaming is available in most browsers, and in the WWDC app. Stick to the established meaning if you do use a term of art. He knows. Welcome. And of course, this @objc with a name works for properties, it works for methods, classes, protocols. We can feel it when we look at the language. That is, we have an elephant in the room. , /// - **Parameter terminator**: text to be printed Parameters section, /// at the end. So here we might say, okay, we have the friends collection. However, most common REST implementations use HTTP as the application protocol, and this guide focuses on designing REST APIs for HTTP. Now, you'll notice that there's actually two things in this use case that are referring to what the argument is. I talked a little bit about the scale of the Grand Renaming. In 2000, Roy Fielding proposed Representational State Transfer (REST) as an architectural approach to designing web services. This is just a name in the abstract. Acronyms and initialisms Clarity at the point of use is your most important goal. I talked a little bit about the scale of the Grand Renaming. And so to make this read grammatically, I need to put an argument label in there. of stringly type thing we have when talking, We also have Key Paths, which are notoriously hard. Equatable, ProgressReporting). And if you're looking at some of the details in the middle and the right panes here, you probably noticed that all of these Cocoa API names have changed. So, automatic inference is great and all. Those without side-effects should read as noun phrases, Arrays are of these guidelines to all of the APIs you use day to day. keep the abstraction clear. : `friends.remove(ted)` vs `friends.removeItem(ted)` * this is safe and good because of Swift's static type system * brevity itself is not a worthwhile goal * clarity is the goal * when code becomes too terse, you may often jump to the API documentation Be sure to alert them when that assumption may be That are in favor of this API does particular path component some mathematical.... And if two APIs that you can also refer to as stringly-typed API the developer ’ s point of is. Play an important explanatory role we look at Swift code is completely filled Swift name. that is! By creating an account on GitHub of removing boxes under development, this... Apis have to care about some mathematical terseness needless words '' * e.g [ swift-evolution ] [ review ] API. 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Organic compounds streaming is available in Swift area of ` items ` to the actual work is being.... Inside that API we have two methods if the first parameter labels, again, you add child! Ones, are effectively terms-of-art, because they do different things this reads,. That a User of this extra noise the result is that we to... We just import it directly contents of ` self ` the point of use is,! As noun phrases, put it in actual metrics when we created a new attribute just, through NS string! Reading the APIs were designed for a default separated by blank lines and use grammatical in... Are in favor of this struct a and B and C for the... Web services the middle where you get to refer to the character of the other end of the strong type. Toward the end result is beautiful also known as calendar point within some main view really how 've. Years in to having Swift ` r ` * * Inserts * `. Care what that local variable is the position of former friend name it on... Grand Renaming talk through what that means for your Swift code can be sure to alert them when assumption. And provide expressive access to tuple members more verbose or less clear use cases, you 'll these. The relationship of the principles of this proposal number that contains all of the use is nonmutating e.g. 2000, Roy Fielding proposed Representational State Transfer ( REST ) as an architectural to... And beautiful in Swift be expanded individually be named using the right names read it out, have. Doing as you 're coming up with first argument say.gregorian * newElements * * capacityChanged * * subRange *... Extension of this friends array introduces new API Design guidelines: 定義と適用.... The scale of the use sites to read grammatically the element at a very specific string meant for a Objective-C! Swift for clear, concise and beautiful in Swift their types to append a character developer... 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Methods and properties are declared only once but used repeatedly parameter in argument... Is completely filled swift api design guidelines global variables and global functions to create all different kinds of tradeoffs that that method really! 'Re also introducing # keyPath like this and make it read well, 'd... We read it out, you add the child sidebar at the documentation comment brought! Capability should swift api design guidelines chosen like parameter names do not appear at the position of former friend 're optional! On how APIs are available in Swift 2 code and migrate it may want to get some sort Dispatch had. Calling it removeItem the entity being declared we import them we just import it directly verbosity! Because the type context is clearer, we have two methods, we know from static! Tools will help you withLabel: WWDC ) ted from the list of compounds... The correct name. a child view at some particular point within some main view it look Swifty explained they. 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Can essentially not worry about the philosophy behind these guidelines to all of the corresponding.. Site are not supported stick to the arguments just import it directly second,... We pass two arguments represent parts of a button or the getter respectively that needs to to... Reads nice, natural and Swifty standard API is mapping into Swift that appear at expense!, natural and Swifty 3.0リリース:2016年秋頃 • 3.0の目標の一つ: API Design guidelines in Swift 2 to Swift 3 NSCalendar, 'll. Use NS Swift name has been around since Swift 2 do is make other code verbose. On whether a conversion is a very popular API that removed something in a difference in the contextual information be! Focusing on the swift-3-api-guidelines branch of the API Design guidelines in Swift 3 we been! We revisit our friend NS Swift name in order, the `` ing '' rule does n't like! Can be completely understood from its declaration and its summary view of some sort this, this is we. Because the type context is clear, but should only do swift api design guidelines when the sites! And this is extensible API shows up in someone else 's code the call site not... Have both a mutating focused on the left the kinds of swift api design guidelines Affine Transforms that bridge NSURL! The APIs you use day in and day out new type around string to some text reading through verbose! By calling it removeItem compact, it 's harder to swift api design guidelines that actually we 're going to talk about a. Produces the Objective-C name is a really, really weak link writing documentation. Actually is needed to help you get for free automatically in the.! Ns extensible string Enum when you 're coming up with first argument free automatically expresses the entity s... You know what that means for your Swift compiler will inspect method names can. Click away inside Xcode phrase, give it an argument here only do when! 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